基于保留边缘的à-Trous小波修正单一图像去雾
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摘要
为解决有雾场景图像复原过程中目标边缘存在细节模糊及丢失的问题,结合暗原色先验理论、引导图像滤波和保留边缘的à-Trous小波滤波方法,提出一种保留边缘的à-Trous小波修正的单一图像去雾算法。先对暗原色先验的引导图像滤波去雾算法进行复现,再引入保留边缘的à-Trous小波滤波算子,用三级小波滤波后的残差结果补偿暗原色先验的引导图像滤波算法去雾的结果。实验结果表明,相较于暗原色先验的引导图像滤波去雾算法,采用可见边对比度作为客观衡量标准,新增的可见边之比至少提高69.5%,可见边的规范化梯度均值提高30%,饱和黑色或白色像素点的百分比降低一半以上。通过主观辨识,去雾算法生成的结果中保留了图像的边界和纹理细节信息,恢复出来的图像颜色更贴近实际生活,去雾效果有较大改善,纹理边缘更加细腻。
In order to solve the problem of blurred and lost target edges in the recovery process of fog scene images,we propose a single image dehaze method based on à-Trous wavelet,which is combined with the dark channel prior theory,guided filter,and edge preserving à-Trous wavelet filtering method.The dehaze algorithm of guiding filtering on dark channel prior is reproduced.Then,we introduce edge preservingà-Trous wavelet filter into the dehaze algorithm,and adopt the three level wavelet filtered residuals to compensate for the guide image filtering algorithm with the dark channel prior.Experimental results show that,compared with the guided image filtering haze removal algorithm based on dark channel prior,the rate of new visible edges is increased by 69.5% at least,the normalized gradient mean of the visible edge is increased by 30%,and the percentage of the saturated black or white pixels is reduced by a half at least,when visible edge contrast is used as an objective criterion.The proposed method can retain the edge and texture details of image while removing haze,and the restored image color is closer to the real life.The effect of dehaze is improved,and the edge of the texture is more delicate.
In order to solve the problem of blurred and lost target edges in the recovery process of fog scene images,we propose a single image dehaze method based on à-Trous wavelet,which is combined with the dark channel prior theory,guided filter,and edge preserving à-Trous wavelet filtering method.The dehaze algorithm of guiding filtering on dark channel prior is reproduced.Then,we introduce edge preservingà-Trous wavelet filter into the dehaze algorithm,and adopt the three level wavelet filtered residuals to compensate for the guide image filtering algorithm with the dark channel prior.Experimental results show that,compared with the guided image filtering haze removal algorithm based on dark channel prior,the rate of new visible edges is increased by 69.5% at least,the normalized gradient mean of the visible edge is increased by 30%,and the percentage of the saturated black or white pixels is reduced by a half at least,when visible edge contrast is used as an objective criterion.The proposed method can retain the edge and texture details of image while removing haze,and the restored image color is closer to the real life.The effect of dehaze is improved,and the edge of the texture is more delicate.
引文
[1]Fattal R.Single image dehazing[J].ACMTransactions on Graphics,2008,27(3):72.
[2]He K,Sun J,Tang X.Single image haze removal using dark channel prior[J].IEEE Transactions on Pattern Analysis and Machine Intelligence,2011,33(12):2341-2353.
[3]Lin Z,Wang X.Dehazing for image and video using guided filter[J].Open Journal of Applied Sciences,2012,2(4):123-127.
[4]Zeng J X,Yu Y L.Image defogging and edge preserving algorithm based on dark channel prior and bilateral filtering[J].Journal of Image and Graphics,2017,22(2):147-153.曾接贤,余永龙.双边滤波与暗通道结合的图像保边去雾算法[J].中国图象图形学报,2017,22(2):147-153.
[5]He K,Sun J,Tang X.Guided image filtering[J].IEEE Transactions on Pattern Analysis and Machine Intelligence,2013,35(6):1397-1409.
[6]Xiao J S,Gao W,Zou B Y,et al.Image dehazing based on sky-constrained dark channel prior[J].Acta Electronica Sinica,2017,45(2):346-352.肖进胜,高威,邹白昱,等.基于天空约束暗通道先验的图像去雾[J].电子学报,2017,45(2):346-352.
[7]Holschneider M,Kronland M R,Morlet J,et al.Areal-time algorithm for signal analysis with the help of the wavelet transform[M].Berlin:Springer Verlag,1989:280-298.
[8]Dai S B,Xu W,Piao Y J,et al.Remote sensing image defogging based on dark channel prior[J].Acta Optica Sinica,2017,37(3):0328002.代书博,徐伟,朴永杰,等.基于暗原色先验的遥感图像去雾方法[J].光学学报,2017,37(3):0328002.
[9]Yang A P,Bai H H.Nighttime image defogging based on the theory of Retinex and dark channel prior[J].Laser&Optoelectronics Progress,2017,54:041002.杨爱萍,白煌煌.基于Retinex理论和暗通道先验的夜间图像去雾算法[J].激光与光电子学进展,2017,54(4):041002.
[10]Li J T,Zhang Y J.Improvements of image haze removal algorithm and its subjective and objective performance evaluation[J].Optics and Precision Engineering,2017,25(3):735-741.李佳童,章毓晋.图像去雾算法的改进和主客观性能评价[J].光学精密工程,2017,25(3):735-741.
[11]Hautière N,Tarel J P,Aubert D,et al.Blind contrast enhancement assessment by gradient ratioing at visible edges[J].Image Analysis&Stereology,2011,27(2):87-95.
[12]Fattal R.Edge-avoiding wavelets and their applications[J].ACM Transactions on Graphics,2009,28(3):22.
[13]Gao K,Chen H X,Zhao Y,et al.Depth map filtering and upsampling method for virtual view rendering[J].Journal of Image and Graphics,2013,18(9):1085-1092.高凯,陈贺新,赵岩,等.面向虚拟视点绘制的深度图滤波及上采样方法[J].中国图象图形学报,2013,18(9):1085-1092.
[2]He K,Sun J,Tang X.Single image haze removal using dark channel prior[J].IEEE Transactions on Pattern Analysis and Machine Intelligence,2011,33(12):2341-2353.
[3]Lin Z,Wang X.Dehazing for image and video using guided filter[J].Open Journal of Applied Sciences,2012,2(4):123-127.
[4]Zeng J X,Yu Y L.Image defogging and edge preserving algorithm based on dark channel prior and bilateral filtering[J].Journal of Image and Graphics,2017,22(2):147-153.曾接贤,余永龙.双边滤波与暗通道结合的图像保边去雾算法[J].中国图象图形学报,2017,22(2):147-153.
[5]He K,Sun J,Tang X.Guided image filtering[J].IEEE Transactions on Pattern Analysis and Machine Intelligence,2013,35(6):1397-1409.
[6]Xiao J S,Gao W,Zou B Y,et al.Image dehazing based on sky-constrained dark channel prior[J].Acta Electronica Sinica,2017,45(2):346-352.肖进胜,高威,邹白昱,等.基于天空约束暗通道先验的图像去雾[J].电子学报,2017,45(2):346-352.
[7]Holschneider M,Kronland M R,Morlet J,et al.Areal-time algorithm for signal analysis with the help of the wavelet transform[M].Berlin:Springer Verlag,1989:280-298.
[8]Dai S B,Xu W,Piao Y J,et al.Remote sensing image defogging based on dark channel prior[J].Acta Optica Sinica,2017,37(3):0328002.代书博,徐伟,朴永杰,等.基于暗原色先验的遥感图像去雾方法[J].光学学报,2017,37(3):0328002.
[9]Yang A P,Bai H H.Nighttime image defogging based on the theory of Retinex and dark channel prior[J].Laser&Optoelectronics Progress,2017,54:041002.杨爱萍,白煌煌.基于Retinex理论和暗通道先验的夜间图像去雾算法[J].激光与光电子学进展,2017,54(4):041002.
[10]Li J T,Zhang Y J.Improvements of image haze removal algorithm and its subjective and objective performance evaluation[J].Optics and Precision Engineering,2017,25(3):735-741.李佳童,章毓晋.图像去雾算法的改进和主客观性能评价[J].光学精密工程,2017,25(3):735-741.
[11]Hautière N,Tarel J P,Aubert D,et al.Blind contrast enhancement assessment by gradient ratioing at visible edges[J].Image Analysis&Stereology,2011,27(2):87-95.
[12]Fattal R.Edge-avoiding wavelets and their applications[J].ACM Transactions on Graphics,2009,28(3):22.
[13]Gao K,Chen H X,Zhao Y,et al.Depth map filtering and upsampling method for virtual view rendering[J].Journal of Image and Graphics,2013,18(9):1085-1092.高凯,陈贺新,赵岩,等.面向虚拟视点绘制的深度图滤波及上采样方法[J].中国图象图形学报,2013,18(9):1085-1092.